Black Capped Chickadees may be small, but they are incredibly tough and can withstand the harsh winters of the Rockies. Here is how these little birds are able to stay warm enough at night during winter.
During winter on a sunny day one of the birds that you may see is the small Black Capped Chickadee. These tiny birds have a big, round head with what looks like a black cap on it. You may see them perched on a tree getting warm or looking for food. I think it is incredible that so many animals migrate or hibernate in order to survive the winters, but not these little guys. They have some very good strategies to survive and I think they are one of the toughest and under appreciated animals in the Rockies.
They Adapt Their Diet
During the summer Chickadees eat mostly insects, caterpillars, and spiders. But, during the winter those foods are not as readily available and they will eat anything they can find. This includes berries, seeds, and even scavenging off dead animals.
They Use A Few Tricks To Stay Warm At Night
Thick Winter Coats – Chickadees replace their feathers at the end of the summer. This means that they have new, thick feathers for the winer.
In addition to having new feathers, they are also good at fluffing out their feathers. This fluffing of the feathers holds in more heat and keeps them warmer.
As a reminder, birds have three main types of feathers – down, flight, and sensory. Those down feathers are what allow them to stay warm. When they fluff out, they are creating space to hold in air close to their body, which will then heat up and keep them warm. This is how our fancy down sleeping bags work, which are full of down feathers or some synthetic material.
Lower Their Body Temperature At Night – During very cold nights they stay warm by going under a mild hypothermia, lowering their body temperature by 12 to 15 degrees F. Even with lowering their body temperature they use up a lot of energy at night staying warm.
Incredibly, they use up to 10% of their body weight during the night to stay warm. This means that during the day they need to eat a lot of food – so that they gain back that 10% of their body weight during the day.
Communal Roosting – If the nights become very cold they may roost together in a large flock in trees, logs, or other sheltered places. Staying together in a large flock with other birds helps them stay warmer than if they were alone.